Bearing

ABSTRACT

A movable member made from a relatively hard material is provided with a first surface. A bearing liner provided with relatively thin, hard and incompressible characteristics is attached to the first surface. A stationary member made from a harder material than the movable member is provided with a polished bearing surface which abuts the bearing liner. Means retain the members in an optimal bearing relationship. 
     The members may be annular and may have a nested relationship. The retaining means may include a pair of stationary sleeves made from a material similar to the movable member and abutting each other at one end. Each of the sleeves may have a flange abutting axial extremities of the movable and stationary members. A pair of additional thin, hard and incompressible bearing liners may be respectively attached to the sleeve flanges at positions abutting the axial extremities of the movable and stationary members. 
     In another embodiment, the stationary member is provided with a flange at one lateral extremity and a single sleeve is provided with a flange at the opposite lateral extremity. The additional bearing liners may be attached to the movable members at positions abutting the flanges.

This invention relates to bearings and more particularly relates tobearings having a relatively simple construction and providing a longand maintenance-free life.

Aircraft now in use specify that moving parts shall be able to operatefor long periods of time with relatively little or no maintenance. Forexample, bearings providing for the operation of ailerons on aircraftshould be able to operate through tens of thousands of revolutionswithout any maintenance. This is particularly important to minimize thecosts of operating the aircraft now that fuel costs have become soexpensive.

The precision bearings now in use are generally needle bearings. Thebest needle bearings now in use generally have a life of approximatelythirty thousand (30,000) revolutions. Furthermore, the needle bearingshave to be greased after every five thousand (5,000) revolutions. Theneedle bearings have such a limited life even though the airlinesspecify that the bearings should be able to operate for as many as onehundred and sixty five thousand (165,000) revolutions without anymaintenance.

A substantial effort has been made for a considerable period of time toprovide bearings which will meet the objectives of the airlines. Inspite of such substantial efforts, the objectives are far from beingattained. As a result, the operation of many key components in theairplanes still have to be serviced regularly by maintenance personnelof the airlines, with the resultant possibility that unsatisfactoryoperation of such components from the negligence or oversight of suchpersonnel will result. Furthermore, the cost of providing suchmaintenance are prohibitive.

This invention provides a bearing which more than meets the airlineobjectives. For example, the bearings are able to operate satisfactorilyfor at least one hundred and sixty five thousand (165,000) revolutionswithout any servicing by airline personnel. Actually, the bearings areable to operate through a considerably greater number of revolutionsthan that specified above without maintenance. Furthermore, the bearingsare relatively simple in construction and easy to manufacture.

In one embodiment of the invention, a movable member is made from arelatively hard material and is provided with a first surface. A bearingliner is attached to the first surface and is provided with relativelythin, hard and incompressible characteristics. A stationary member madefrom a harder material than the movable member is provided with abearing surface which is polished and which abuts the bearing liner.Means retain the movable and stationary members in an optimal bearingrelationship.

The movable and stationary members may be annular and may have a nestedrelationship so that the bearing surfaces are annular and the movablemember is rotary. The retaining means may include a pair of stationarysleeves made from a similar material to the movable member and abuttingeach other at an intermediate position along the axial lengths of thebearing surfaces. Each of the sleeves may have a flange abutting axialextremities of the movable and stationary members. A pair of additionalbearing liners may be respectively attached to the sleeve flanges atpositions abutting the axial extremities of the movable and stationarymembers. Each of the additional bearing lines may be relatively thin,hard and incompressible.

In another embodiment of the invention, the stationary member isprovided with a flange at one lateral extremity and a single sleeve isprovided with a flange at the opposite lateral extremity. The additionalbearing liners may be attached to the movable member at positionsabutting the flanges.

In the drawings

FIG. 1 is a perspective view, partially broken away in section, of abearing constituting one embodiment of the invention;

FIG. 2 is an enlarged sectional view of the bearing shown in FIG. 1;

FIG. 3 is a sectional view similar to that shown in FIG. 2 but alsoshowing schematically apparatus for driving the rotary member in thebearing; and

FIG. 4 is a sectional view of a second embodiment of the invention.

In one embodiment of the invention, a bearing generally indicated at 10is provided. The bearing includes a movable member 12 made from arelatively hard member such as a 17-4 PH steel. The member 12 ispreferably annular and hollow. When the member 12 is annular, a surface14 may be annular and may be disposed at the inner surface of themember. Means 16 are provided for producing a movement of the member 12.

A bearing liner 18 is attached to the surface 14. The bearing liner 18is preferably thin, hard and incompressible and is provided with asubstantially uniform thickness. The bearing liner may be constructed asdescribed in U.S. Pat. Ser. Nos. 3,594,049 and 3,900,408 respectivelyissued to Peter Turner on July 20, 1971 and Aug. 19, 1975 and assignedof record to the assignee of record of this application.

A stationary member 20 has a polished surface 22 disposed in fricitionalrelationship with the bearing liner 18. The stationary member 20 isannular when the member 12 is annular. The member 20 is preferably madefrom a harder material, such as a 440 C steel, than the member 12.

Retaining means may also be included in the bearing. The retaining meansmay include a pair of sleeves 24 and 26. The sleeves 24 and 26 may bemade from the same material as the movable member 12 or the stationarymember 20. The sleeves 24 and 26 abut each other at an intermediateposition along the axial length of the member 20.

The sleeves 24 and 26 are respectively provided with flanges 28 and 30which abut the axial extremities of the members 12 and 20. Bearingliners 32 and 34 are respectively disposed between the flange 28 and theaxial extremities of the members 12 and 20 and between the flange 30 andthe axial extremities of the members 12 and 20. The bearing liners 32and 34 may have the same composition and characteristics as the bearingliner 18.

The sleeves 24 and 26 are provided with dimensions to limit the side (oraxial) play or lateral wobble of the members 12 and 20. This control ofthe side wobble is important in inhibiting the imposition of any stressupon the bearing liner 18. In this way, the life of the bearing liner isenhanced.

The disposition of the bearing liner on the rotatable member 12 and theformation of the liner from a thin, hard and incompressible material areimportant in providing the bearing with a long and maintenance freelife. For example, the liner 18 is subjected to an even wear as itrotates past any load points on the stationary member 20. Furthermore,since the liner 18 is thin, hard and incompressible, it does notcompress and expand as it moves past the load points on the stationarymember. This is important in limiting any fatigue on the bearing liner.

Tests of the bearing described above have shown that the bearing hasbeen able to withstand at least one hundred and sixty five thousand(165,000) revolutions without any maintenance. In that period, only halfof the thickness of the liner has been worn away. This would indicatethat the bearing should be able to withstand at least three hundredthousand (300,000) revolutions without any maintenance. This is incontrast to bearings now in use. These bearings have to be regreasedevery five thousand (5,000) revolutions and still have an average lifeexpectancy of only approximately thirty thousand (30,000) revolutions.

The liners 32 and 34 are provided as a precautionary measure to insurethat the member 12 will not rub against the flanges 28 and 30 when themember 12 rotates. The bearing liners 32 and 34 are extended into thespace between the member 20 and the flanges 32 and 34 to maintain properspacing between these members.

FIG. 4 illustrates a second embodiment of the invention. In thisembodiment, a movable member 100 may be constructed as described abovefor the movable member 12 in the previous embodiment. However, bearingliners 102 and 104 may be attached to the lateral extremities of themovable member. The bearing liners 102 and 104 correspond to the liners32 and 34 in the previous embodiment.

A stationary member 108 in FIG. 4 corresponds to the stationary member20 in the previous embodiment. The stationary member may be provided atone lateral extremity with a flange 110 which abuts the bearing liner102. A sleeve 112 provides substantially the same functions as thesleeves 24 and 26 in the previous embodiment. The sleeve 112 is providedwith a flange 114 at the lateral extremity opposite the flange 110. Theflange 114 abuts the bearing liner 104.

Although this application has been disclosed and illustrated withreference to particular applications, the principles involved aresusceptible of numerous other applications which will be apparant topersons skilled in the art. The invention is, therefore, to be limitedonly as indicated by the scope of the appended claims.

I claim:
 1. In combination,a movable member made from a relatively hardmaterial, a bearing liner disposed on a first particular surface of themovable member in a thin layer and provided with relativelyincompressible characteristics and with characteristics of resistingwear and fatigue, and a stationary member made from a relatively hardermaterial than the movable member and disposed in frictional relationshipwith the bearing liner, means disposed on the opposite side of thestationary member from the movable member for retaining the atationarymember against the movable member and for inhibiting any lateral wobblebetween the stationary and movable members, the retaining means beingformed from a pair of sleeves abutting each other at an intermediateposition and abutting the movable and stationary members at theirextremities.
 2. The combination set forth in claim 1 whereinadditionalbearing liners are disposed on the pair of sleeves at the extremitiesabutting the movable and stationary members.
 3. In combination,a hollowannular member made from a relatively hard material and provided with afirst surface, a second annular member made from a harder material thanthe hollow annular member and provided with a second surface in abuttingrelationship to the first surface, a bearing liner attached to the firstsurface and engaging the second surface, the bearing liner being hard,thin and relatively incompressible and being provided withwear-resistant properties, and means for retaining the hollow member andthe second member in a relationship in which the bearing liner abuts thesecond member, the second surface being polished and the bearing linerbeing provided with a uniform thickness, the second annular memberhaving an additional surface opposite the second surface and theretaining means being disposed against the additional surface of thesecond member.
 4. The combination set forth in claim 3 whereintheretaining means is formed from a pair of sleeves abutting each other atan intermediate position along the length of the additional surface andwherein each of the sleeves includes a flange disposed against a lateralextremity of the hollow and second members.
 5. The combination set forthin claim 4 whereinadditional bearing liners are disposed on the flangesof the sleeves and the additional bearing liners have substantially thesame characteristics as the first bearing liner.
 6. In combination,afirst annular member provided with relatively hard characteristics andwith a first surface, a second annular member provided with hardercharacteristics than the first annular member and with a bearing surfacecontiguous to the first surface, the first and second members beingdisposed in nested relationship, a bearing liner disposed on the firstsurface in frictional relationship with the bearing surface on thesecond member, means for providing a rotation of the first annularmember, and means for retaining the first and second members in a nestedrelationship, the retaining means restricting the first and secondmembers against a relative wobble during rotary movement of the firstmember, the retaining means including a pair of sleeves abutting eachother at an intermediate position along the axial lengths of the bearingsurfaces on the first and second members and each of the sleeves havinga flange portion contiguous to one of the axial extremities of the firstand second members.
 7. The combination set forth in claim 6 whereinthebearing liner is relatively thin, hard and imcompressible and wherein apair of additional bearing liners are provided and each of theadditional liners is attached to the flange of one of the sleeves inabutting relationship with the axial extremities of the first and secondmembers and each of the additional bearing liners is relatively thin,hard and incompressible.